1 This directory contains board specific code for a generic MPC860T based
2 embedded computer, called 'GEN860T'. The design is generic in the sense that
3 common, readily available components are used and that the architecture of the
4 system is relatively straightforward:
6 One eight bit wide boot (FLASH) memory
7 32 bit main memory using SDRAM
10 Some I2C peripheral devices: Atmel AT24C256 EEPROM, Maxim DS1337 RTC.
11 Some other miscellaneous peripherals
13 NOTE: There are references to a XIlinx FPGA and Mil-Std 1553 databus in this
14 port. I guess the computer is not as generic as I first said 8) However,
15 these extras can be safely ignored.
17 Given the GEN860T files, it should be pretty easy to reverse engineer the
18 hardware configuration, if that's useful to you. Hopefully, this code will
19 be useful to someone as a basis for a port to a new system or as a head start
20 on a custom design. If you end up using any of this, I would appreciate
21 hearing from you, especially if you discover bugs or find ways to improve the
22 quality of this U-Boot port.
24 Here are the salient features of the system:
25 Clock : 33.3 Mhz oscillator
26 Processor core frequency : 66.6 Mhz if in 1:2:1 mode; can also run 1:1
27 Bus frequency : 33.3 Mhz
33 Chip : Two Micron MT48LC16M16A2TG-7E
34 CS : MPC860T CS1*/UPMA
45 Chip : One Intel 28F128J3A (StrataFlash)
46 CS : MPC860T CS0*/GPCM (this is the "boot" chip select)
49 Type : Serial I2C EEPROM
52 Chip : One Atmel AT25C256
53 CS : 0x50 (external I2C address pins on device are tied to GND)
56 Type : NAND FLASH (Toshiba)
57 Width : 8 bits (i.e. interface to DOC is 8 bits)
59 Chip : One DiskOnCHip Millenium Plus (DOC 2000+)
60 CS : MPC860T CS2*/GPCM
63 MAC : MPC86OT FEC (Fast Ethernet Controller)
65 MII Addr: 0x0 (hardwired on the board)
69 RS-232 on SMC1 (Maxim MAX3232 LVCMOS-RS232 level shifter)
72 Type : Low power, I2C interface
74 CS : Address 0x68 on I2C bus
76 The MPC860T's internal RTC has a defect in Mask rev D that increases
77 the current drain on the KAPWR line to 10 mA. Since this is an
78 unreasonable amount of current draw for a RTC, and Motorola does not
79 plan to fix this in future mask revisions, a serial (I2C) RTC that
80 works has been included instead. NOTE that the DS1337 can be
81 configured to output a 32768 Hz clock while the main power is on.
82 This clock output has been routed to the MPC860T's EXTAL pin to allow
83 the internal RTC to be used. NOTE also that due to yet another
84 defect in the rev D mask, the RTC does not operate reliably when the
85 internal RTC divisor is set to use a 32768 Hz reference. So just use
89 Xilinx Virtex FPGA on CS3*/GPCM.
90 Virtex FPGA slave SelectMap interface on cs4*/UPMB.
91 Mil-Std 1553 databus interface on CS5*/GPCM.
92 Audio sounder (beeper) with digital volume control connected to SPKROUT.
95 A reduced-feature version of the GEN860T port is also supported: GEN860T_SC.
96 The 'SC' variant only provides support for the Virtex FPGA, SDRAM main
97 memory, EEPROM and flash memory. The system clock frequency is reduced
101 The DOC 2000+ returns 0x40 as its device ID when probed using the method
102 desxribed in the DOC datasheet. Unfortunately, the U-Boot DOC driver
103 does not recognize this device. As of this writing, it seems that MTD
104 does not support the DOC 2000+ either.
107 Everything appears to work except DOC support. As of this writing,
108 David Woodhouse has stated on the MTD mailing list that he has no
109 knowledge of the DOC Millineum Plus and therfore there is no support
110 in MTD for this device. I wish I had known this sooner :(
112 The GEN860T board specific files and configuration is based on the work
113 of others who have contributed to U-Boot. The copyright and license notices
114 of these authors have been retained wherever their code has been reused.
115 All new code to support the GEN860T board is:
117 (C) Copyright 2001-2003
118 Keith Outwater (keith_outwater@mvis.com)
120 and the following license applies:
122 This program is free software; you can redistribute it and/or
123 modify it under the terms of the GNU General Public License as
124 published by the Free Software Foundation; either version 2 of
125 the License, or (at your option) any later version.
127 This program is distributed in the hope that it will be useful,
128 WITHOUT ANY WARRANTY; without even the implied warranty of
129 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
130 GNU General Public License for more details.
132 You should have received a copy of the GNU General Public License
133 along with this program; if not, write to the Free Software
134 Foundation, Inc., 59 Temple Place, Suite 330, Boston,
137 Thanks to Wolfgang Denk for a great software package and to everyone
138 who contributed to its development.
143 <keith_outwater@mvis.com>
144 <outwater@eskimo.com>
146 vim: set ts=4 sw=4 tw=78: